Let \( f \) be the function defined by
\[
f(x) = \begin{cases}
x^2 - 1, & x \neq 1 \\
x^2 - 2|x-1|^{-1}, & x = 1
\end{cases}
\]
The function is continuous at:
Show Hint
To check for continuity, ensure that the function is defined at the point and that the left-hand limit, right-hand limit, and function value all match.
By evaluating the function and considering the behavior at \( x = 1 \), the function is not continuous at any point.
Final Answer:
\[
\boxed{\text{None of these}}
\]